The mechanisms that cause glaucoma are not completely known, though glaucoma has been linked to abnormally high pressure in the eye, which can lead to optic nerve damage. Over time, the increased pressure can cause damage to the optic nerve, which can lead to blindness. Treatment strategies have focused on keeping the intraocular pressure down in order to preserve as much vision as possible over the remainder of the patient's life.
Pursuant to such strategies, one or more implants can be delivered into the eye for shunting fluid out of the anterior chamber in order to regulate pressure in the eye. Accurate placement of an implant in the eye can be critical for the targeted effect of reducing intraocular pressure (IOP). For example, incorrectly placing an implant can inhibit aqueous outflow, such as if the incorrectly placed implant does not provide fluid communication with the flow target location.
Additionally, an ocular implant incorrectly placed in the eye, such as where a significant portion of the implant remains in the anterior chamber, damage to the corneal endothelium can result. For example, some incorrectly placed ocular implants, including implants that migrated after implantation, such as positioned too proximal in the angle of the ye, can touch the iris resulting in increased amounts of pigment dispersion in the eye which can increase outflow resistance and intraocular pressure by clogging the trabecular meshwork. Therefore, correct placement of the implant is desired for a safe and a successful surgical outcome.
Additionally, in at least some instances, reduction in IOP can be correlated with forming one or more areas of separation between parts of the eye, such as between the choroid and sclera. These areas of separation can at least assist in allowing fluid to flow from the anterior chamber of the eye to the suprachoroidal space or supraciliary space. However, although creating separation between parts of the eye may be beneficial, creating larger incisions in the eye is generally not. For instance, a larger diameter implant may be able to create greater separation between parts of the eye, such as between the sclera and choroid, but a larger incision would be necessary which can result in excess tissue damage to the eye.
Furthermore, after the implant has been implanted in a target location within the eye at least some of the tissue surrounding the implant can have a variety of responses to the presence of the implant. For example, some of the surrounding tissue can respond to the presence of the implant by proliferating tissue growth, such as connective tissue, around parts of the implant. Some tissue growth surrounding the implant can be beneficial for assisting in anchoring the implant and preventing implant migration. However, some tissue growth can impede fluid flow, including either through or surrounding the implant.
In view of the foregoing, there is a need for improved ocular implants which are compact enough such that they do not require a large incision for implantation but can provide improved separation between one or more parts of the eye, such as between the sclera and choroid, as well as assist in promoting fluid flow from the anterior chamber of the eye to the at least one of the suprachoroidal and supraciliary space. Additionally, there is a need for an implant to assist in controlling the tissue response of at least some of the tissue surrounding the implant in order to maintain an improved fluid flow created by the implant and reduce IOP.